#include <iostream>
#include <string>
#include <sstream>
#include <cctype>
#include <set>
#include <cstdlib>
using namespace std;

int main() {
//    ios_base::sync_with_stdio(false);cin.tie(nullptr);
    string in;
    set<string> ans;
    while(getline(cin, in)){
        for (char & i : in) {
            if(isalpha(i)) i = tolower(i);
            else i = ' ';
        }
        stringstream ss(in);
        string word;
        while(ss >> word){
            ans.emplace(word);
        }
    }
    for (const auto &item : ans) {
        cout << item << "\n";
    }
    return 0;
}